Unless your pool is purposely drained, most water that you add to it will never become wastewater. In general, most pools seldom require draining except for the occasional cleaning and repair. However, in areas where the water contains a high concentration of total dissolved solids (TDS) or in colder climates, pools will often be drained on a yearly basis. If you are draining your pool, never drain it directly into a storm sewer or a nearby lake or stream. Pool water contains chemicals, including chlorine, which can be harmful to aquatic ecosystems.

When draining your pool, you have two options: use the water to irrigate your landscape or drain the water into a sanitary sewer. If you are unsure of what method is right for you, you may want to consult with a city official or a pool industry professional before proceeding. To use the water for irrigation, let the pool sit for a few days without adding any chemicals (this allows the chlorine to vaporize). Then you can slowly drain some of the water onto your yard. However, be sure that it does not produce runoff into the streets or storm sewers. Alternatively, you can drain the water into a sanitary sewer. Below is a step by step method of draining your pool into a sanitary sewer that was developed by the Southern Nevada Water Authority:

Shut off the power to the circulation system at the circuit breaker.

Locate the clean-out port to access the sanitary sewer line. The port is usually located in the ground and close to the home in the front yard—it may be near a water spigot. The port should have a rubber or threaded cap with a square wrench fitting and should be three to four inches in diameter. If you can't locate the port, contact a plumber. (Caution: Using a clean-out in the wall creates greater potential for water to back up into the house.)

Run a drainage hose from the sewer clean-out port to the pool, and connect it to a submersible pump. Lower the pump into the deepest part of the pool, near the drain. As you begin draining, monitor the water's flow into the clean-out port to ensure that the water doesn't back up. If the water begins to back up, stop draining and contact a professional plumber. The maximum recommended discharge rate is 12 gallons per minute. (Note: Any hoses or equipment inserted into the sewer line can become contaminated.)

After draining your pool, refill it as soon as possible. Direct sunlight can damage the plaster in your pool if it's left exposed. It may take a few days for the fresh water to reach the proper chemical levels, so check the levels every day for a week and add chemicals as needed.

If you're unsure about draining your pool, or you'd like assistance, contact a professionally-licensed pool service company or plumber. By following these guidelines, you can ensure your drained pool water is properly treated and recycled.